Method of and apparatus for applying coatings



Nov. 30 1926.

T. BIRKENMAIER ET AL METHOD OF AND APPARATUS FOR APPLYING COATINGS Filed August 19, 1921 4 Sheets-Sheet 1 m. y ,ff .W ux raw i540. MF a., 7, 11M, 9 0- w 7W@ Nov. 30 1926. 1,608,833

T. BIRKENMAIER ET AL METHOD OF AND APPARATUS OR APPLYING COATINGS Filed August 19. 1921 4 SheetsSheet 2 /Zf /4 /j l//l Nov. 30,1926. 1,608,833

T. BIRKENMAIER ET AL METHOD OF AND APPARATUS FOR APPLYING COATINGS Filed August 19', 1921 4 sheets-sheep :s 1,40 1.60 Ft, 0.16; 'Z/f'fl/e//'cd/ 'D' Pou/lila "Yagamn/ E313-gg- Nov. 30 1926.

T. BIRKENMAIER ET AL METHOD OF AND APPARATUS FOR APPLYING COATINGS mZ/m M dw w, M Q7 y w m W M u, M o W, MEW EM W W I; ff. #m y www 5 webs a. w 15H ln.. o d WM5 /L My z 5 TWJAW, Je 6. A 5 E verging lateral jets and While this. may b- Patented Nov... 30, 1926.

UNITED ySTATES PATENT OFFICE.

THODOBE BIBKENMAIER, WALTER A. HEINRICH, AND JOHN B. TRECOTT,` 0F S'T.

LOUIS, MISSOURI, ASSIGNORS, BY MESNE ASSIGNMENTS, T0 W. N. MATTHEWS COR- PORATION, 0F ST. LOUIS, MISSOURI, CORPORATION 0F MISSOURI.

Harmon or AND vAPPARATUS, non APPLYINGcoA'rINos.

Application tiled August 19, 1921. Scrial No. 493,708.

\ This invention relates to new and useful improvements in'methods of and apparatus for applying coatings,such as paint or other liquids, paste, powder, 'and the like, the objects being to provide a simple and easily manipulative apparatus whereby the material constituting the coating, and which is ejected under pressure, may bel diverted by a so-called target forming attachment whereby the colum'n`of coating lmay be diverted upwardly, downwardly, to the right, or to the leftfby applying a jet or blast of gaseous Huid, under pressure, such as air,

to the center of the column of coating material being ejected to form a crescentic or semilunar target; or by applying oppositely directed and converging jets or blasts of gaseous Huid, such as-air, under pressure to the edge of the columnv of ejected material and `to diiferent sides of the -axial center thereof, to produce a wide fanlike or ribbon formation of material to the surface being coated; or by applying oppositely directed and converging jets or blasts of gaseous fluid, such as compressed air, to opposite sides of lthe center of the ejected `column of coating to form a narrow fanlike or elliptical form of target; or by further adjustment of saidl target forming attachment, to eject a column of coating which will form a circular target. Heretofore it has been proposed to eject coating material under pressure and toA chano'e its column formation into a more or less attened ellipticallyshaped target by directing diametrically opposlte and converging jets thereagainst at\ points-whose greati est intensity'is coincident with the axial center of the column. These fan-forming jets are directed from-op osite sides against the axial or center-line ci) the column usually at the same pressure as is used to eject the material and will produce y a target of considerably flattened elliptical shape, but on account ofthe intensity of the-opposing jets atfthe center of thecolu'inn, a so-called fishtail target will sometimes result, i. e., a' target wherethe material is lightly and very thinly applied at thementer and more heavily applied at thel sides. It has alsol been proposed to'regulate the pressure of the conviate, to a/certain extent, the fish-tail effect, it at the same time lessens the major axis of the target by producing a fatter ellipse, i. e., one more nearly round.

It is the purpose of our invention to produce circular, unilateral and bilateral targets by the employment of the same apparatus. In the production of the unilateral target, a blast or jet of air under pressure is directed at`an angle, preferably, less than 90 against the column of material ejected under pressure and preferably at a point where the lineof greatest` intensity of the jet or blast intersects the axial line of the column so as to divert or bend the column to one side thus roducin a crescentic or semilunar target. As the lssuing coating material is preferably ejected so as to produce'a target of circular form, it is'clear that a blast or jet of air whose greatest intensity is at its center, directed against the axial line of the column will more effectively divert the column in the production of a semielliptic or crescentic target, because it has,

when so directed at the axial line, a greater production of a wide ribbonlike target.

This different law of operation may be stated to consist in the diverting of the edges only of the columnlike stream of ejected flowing material. These jets or blasts of air are thus eccentrically disposed to the column,

vand their line or. lines of greatest intensity located near the centers thereof, strike the column of material tothe side of its axial line. Thus, the diverting and oppositely directed blasts have no common point of intersection (except possibly at their edges) and are free to pass each otherr so as-to uninterruptedly carry with them portions of the material in the formation of the wide ribbonlikel target. In' this manner, the particles of coating material at or near the center of the column 'are not disturbed, and.

hence, the formation of a. fish-tail target is avoided. Furthermore, the major axis of the Cil elliptical target whose'majo'r axis isfrom` eight to ten inches; whereas where the' jets of air are tangentially disposed and pass each other as contemplated by us, a spray gun operating under the same conditions at the same distance from the surface to be coated, would produce a wide ribbonlike target whose major axis is vfrom twenty-live to thirty inches and whose center is as solid and as evenly coated as its ends.

In the accompanying drawings:

Figure 1 is a side elevational view of our spray gun employed in carrying out our met od;

Figure 2 is a front elevational view thereof showing the target forming attachment;

Figure 3 i's'ua front elevational view thereof, with the target forming attachment removed therefrom;

Figure 4 is a vertical sectional view through the nozzle end of the gun;

Figure `5 is a similar view showing the parts in a changed position;

Figure 6 is a -detail view of the spider plug in the discharge end of the nipple;

Figure 7 is a sectional view ofa modiied form of target forming attachment;

Figure 8 is a front elevational view of the form shown in Figure 7 v Figure 9 i`s`a detail front elevational view of the valve seat;

Figure 10 is an enlarged view of the paint controlling valve stem showing ,the same 'in a position to permit the passage of a large 'supply of paint :into the air passage;

l, Figure 11 is a similar view showing lthe position of the partsiin admitting a small `amount of paint to the ai'r passage;

Figure 12 is a similar view showing the Vposition of the-valve wherein the paint passages are closed and baclrair pressure is permittedto flow through the paint passages; y Figure 13 is a detail side elevational view of the paint controlling valve; Figures I4 to 2 5, inclusive, lare diagrammatlc views showlngidifferent positions of the target forming attachments on thel form of spray gun -illustrated in Figures 1 to 6.

Figures 26 to 37, inclusive, are diagram-Y matic views showing the different positions. of the target forming attachment on the.

form of spray gun illustrated in Figures 7 to 13. v l

In the drawings,.referring particularly to Figures 1 nto 6, lindica'tesa casting resembling a pistol in general shape, on the handle of which is a nipple 2 for supplying air under pressure to the gun. 3 is the nipple to which a paint supply pipe, not shown,

may be connected. T ese air and paint supply pipesare preferably of tubular rubber.

4 is a trigger for controlling the stemsv and 6 of the air and paint valves, respectively. The parts above referred to may all be the same as those disclosed in the Heinrich Patent No. 1,382,640. The compressed air passes through the centrally arranged conduit of the barrelin the end of which is threaded a nipple 7 having a hexagonal head for `well understood purposes. r1`he protruding end of this nipple is preferably cylindrical in form and its orifice contain a spider-like plug 8. `Plug 8 is provided with a central opening for forming a constricted orifice for the jet of air which ejects v the column of material from the gun.

lAround the edges of this plug` are a series ot grooves or recesses 8, the purpose of which is to permit small quantities of air to pass therethrough, thereby keeping thel wall of the `air conduit behind the plug compara-f the forward end of nozzle 9, the outer end of sai-d threaded stem being provided with a knurled head by which the valve may be positioned and adjusted. This valve stem is provided with a differential bore forming a shoulder 10b and when the valve is screwed inwardly, this shoulder is seated against the end of nipple 7, as'shown in Figure 4, thereby preventing paint, or other material, from passing out through the stem; but when said valve is adjusted outwardly, as shown in Figure 5,-the pain/t or other material enters in the rear end of the larger/bore of the valve stem and passes forwardly in the space therebetween and the nipple 7 until it is within the smaller bore of the valve stem, at which time it is ejected in the form of an atomized,tapering'column which will produce a circular target Von the 'surface being painted, and the size and surface coverage depends largely upon the distance the gun is held from the surface being covered, the pressure of air used, the viscosity7 of the aint and the'pressure at which the paint 1s supplied to the nozzle chamber. It is obv-ious that; when the valve member 10 is seated against the end'of the nipple, paint will not be permitted to pass through the restricted oriiice of the valve member; butby lon ' controlled. The further the shoulder` 10b is moved away from the end ofthe nipple, the less friction there will be offered to the paint and consequently the greater the quantity of paint ejected.

l1 indicates a `ring valve seat forming with the barrel an annular airspace or chamber which is in communication with the compressed air conduit of the gun. There are a series of openings or ports through this valve sea-t indicated at 11b. There may be any 'number ot these openings spaced and arandA passing through the crater-like face of an outer portionot the base head ring.

Referring to Figure 2, it will be noted that the ports A and B are diametrically opposed to each other and emit blasts or jets of air on each side of the column of ejected material, and by reference to Figure 4 it will be seen that these jets pass cach other at approximately the same point with respect to the axial line of the column of material.. Port C is indicated by the arrow in Figure 2, and emits a blast of air which is directed against the axial line of the column of material.

The valve seat ring 11 is preferably provided with an arrow or positioninomark, and the base ring 12x of the target orming attachment is .likewise provided with positioning marks, each of the latter having an initial, indicating the character or shape of the target produced when the, target forming attachment is rotatably4 adjusted to locate the roper indiciaopposite the positioning marE on the valve ring seat. For instance, the base ring may be marked around its circumference in connection with thepositioning marks thereon. with the letters aV, aD, Cp Hp Rp aU, and ML, in dicatin g, respectively, vertical, down, column, horizontal', right, up and left.

As shown in Figures 14 to 25, inclusive, somev targets are duplicated in making a complete rotationl of 'the target-forming attachment. This, however, we deem not objectionable because the operator can in this way secure a proper adjustment for a desired target by rotating the target-forming attachment in either direction one half revolution or less.

1 In Figure 14 it'will be seen that .in the formation of a wide vertical ribbon target, the diametrically opposite ports A and B register with diametrically opposite ports 11. The port 'C is closed.

In Figure 15, produced by partial rotation of the target-formino' attachment, ports A and B are closed while port C registers with one of the upper ports 11a to. produce a down-target, i. e., one in which the mat-erial of the ejected column has been diverted downwardl crescentic or semi unar target. This target is advantageously employed in painting floors or other horizontal Surfaces.

In Figure 16, all of the ports A, B and C are closed, and hence a circular target will be produced. l

In Figure 17, the target forming attachment has been adjusted approximately one quarter of a revolution from its attributed starting point, and ports A and B are now brought into play to produce a wide horizontally disposed ribbonlike target.

In Figure 18, b a slight further adjustment, ports A an B are closed and port C is brought intoplay so as .to produce a unlilateral crescentic target to the right of the axial line of the column. This deflection of the target towards the right is advantageously employed in narrow spaces where it is difficult to manipulate vthe gun.

In Figure 19, all of the ports A, B and C are closed and a circular target will thus be produced.

In Figure 20, tlie target forming attachment has been adjusted .until it has reached a position 180o or one half revolution from its starting point, shown in Figure 14, and in which a Wide vertical ribbonlike target is produced.

In Figure 21, ports A and B are closed and port C-isopen to deflect thecolumn upwardly. This up target is advantageously used in painting ceilings and the undersurfaces of large articles of furniture. f

Figures 22 Aand 23 produce column and wide horizontal ribbonlike targets, such as heretofore` described with reference to' Figures 16 and 17 and in Figure 24 a uni-" lateral left target is produced by bringing and forms a unilateral Y iio port C opposite one of the openings 11. This left target is similar to the right hand target produced by theI position of the parts shown in Figure 18,1but, of course, is deflected in an 'opposite/d' eetion. l

In Figuref25 all of .he ports A, B and C lare closed and in this position of the'patsl a circular target will be produced.V A fur! ther adjustmentlof the target-forming 'attachment will produce a wide vertical target such as described with relation to Figure 14.

" It will be-observed that in addition to the adj ustments of the: target-forming attachment just described, other intermediate positions maybe used in the production of other liao and differently shaped targets. For instance, insteadvof relying upon an extra port C Whose jet is directed towards the axial line of the colulnnv in the production of right, left, down and up targets, all unilateral and crescentic, a port similar to one of 'the ports A and B might be employed in the production of a peculiarly` shaped asymmetric target, one end of which is semicircular in form and one side of which is elongated or provided with a tail, the major axis v tion,

` fering with 'the freedom yof rotat-ion, `in

either) direction, of the target forming atltachment.

In Figures 7 to 13, inclusive, We 4have shown a modified form of our invention in which the target forming attachment is provided With a greater number of jet or blast ports (live) while the valve ring seat is provided With a fewer number of ports (four).

In this "construction, 1 is the Vcasting inA which are formed the air and paint conduits as before described controlled by suitable valves (not shown). 11c is the valve ring seat having four ports 11d preferably equidistantly spaced apart, as shown in Figure y 9. 12b is the target-forming member having j port a, b, c, d and e terminating in angularly disposed openings through Which-are projected jets or blasts of air as indicated by the arrows in Figures 7 and 8. 13a is a Washerbearing against the-interior shoulder on the base ring 12y of the target-forming member, and 14 is a lock nut (corresponding in this function to the nozzle 9 heretofore described) which is threaded on the barrel to hold the Washer and targetforming member in position. Instead ofl mounting thel paint controlling valve in the end of the nozzle, as described with respect to the form shown in Figures 1 to 6, inclusive, we adjustably mount said valve by means of the threads on tie end of the nipple 7 a, as shown 'more clearly in Figure 7. The nipple in this form is provided with an annular paint chamber 9b (in connection With thel paint conduit), andthe central bore of the nipple communicates with this painty chamber by means of a plurality of diagoi Inally disposed ports9c. The paint controlling valve has a central bore or orifice 10 of uniform diameter throughout the length of its stem, said stem carrying a' disk l.flange 10d at its outer end by which it may be ro.-l

tated, and, through the medium of the threaded flange 10e, in engagement with the nipple, adjusted longitudinally. The valve stem 10E is provided with a plurality of diagonally disposed 'openings 10g, which, when the valve is in its innermost position, register with the diagonal openings 9c, as shown in Figure 7 (and diagrammatically in Figure 10). In this position of the parts, the

greatest quantity of paint can be drawn by a.

siphoning or suction action into the bore 10c, by the compressed air passing therethrough;

- and, of course, Where drawn into the bore,

-will be forced out by the atomizing stream of air in the form of a tapered (conical) column which will, in the absence of distorting influences, produce an evenly distributed and uniformly applied atonized coating in the forin of .a round or circular target. A slight rotation of the valve st'em will cut ofi' this maximum supply, but We do no not rely upontliis circumferential movement to accomplish this, preferring to gradually cut ofiI the paint supply by a longitudinal displacement of the valve stem (as shown in Figure 11). 'By continuing to unscrew the valve, the ports 1()g will finally be moved out of register .with the ports 9, thus entirely shutting off the supply of paint; and a continued further outward movement of the stem will gradually place the bore of the i nipple in direct communication with the ports 9c, as shown in Figure 12. Inthis position-of the parts, the paint Will be forced back through the ports 9, the paint duct and into the supply tank, where the air pres- 1 sure Will, in addition to clearing and cleaning out these passages, agitate and mix the paint. To obtain' a stronger back pressure, the operator may place his finger over the opening 10c to close it, when the atomizing pressure can be forced back into the paint tank. The target-forming member may also be adjusted to a C (column) get a full back pressure.

In Figure 26, We have shown diagrammatically the W. Vfposition of the targetforming member fin producing a Wide-vertical target. From the position of the arrows leading from ports a and b it will be seen that the jets or blasts of air strike the olumn on each side of its-center or axial me. v

In -Figure 27 is shown the N. I-I. position, whereinnthe ports c and d register with the vertically alig ed valve-seat ports 111 V position to and from the direct on indicated by the ary rows leading troni these ports c and ,it will be observed that the jets or blasts of anl are directed towards the center of the atomized column; hence a narrow-horizontal ins or elliptically-shaped target will be produced. j A

In Figure 28, thev target-forming member iso has' been further adjusted in a clockwise direction to its D position, wherein port e directska'single jet or blast of air downwardly upon and at the center of the column of atomized paint to produce a unilateral or" W. I-I. position vis indicated, in which the ports -a and b are brought into register with the horizontally aligned ports '11 to produce a Wide-horizdntal or solid ribbonlike target.

In Figure 31, the N. V. position has been reached, in .which the ports c and d are in register with the horizontally aligned targets to produce a narrow-vertical target of ellipticalshape.

In Figure 32, the port e is brought into register with one of the ports 11c in the R position, to produce a right or crescentic unilateral target, bulged thusly:

The C (column) .position shownin Figure 33 produces the saine results as shown by the position of the parts in Figure `29 .heretofore/ described: the W. V. (Widevertical) position of the parts shown in Figure 34 will produce the same results described with reference to Figure 26; the ,N. H. (narrow-horizontal) vposition of Figure 35, the same as Figure 27 ,the U (up) position of Figure 36 being the'lrev'erse concentric iofthe D (down) position of. Fig'- ure 28; and the L position of Figure .37 l

producing a left or unilateral target (the reverse of Figure 32)-bulged thusly:

In an application iled'by Walter A. Heinrich May 10, 1921, Serial No. 468,314, Patent apparatus comprising a base ring, parallel No. 1,438,239, there'is disclosed a .fan-forming attachment having a crater-like recessA in its face, in the side wall's'of which are provided vports for emitting blasts of air upon opposite sides of the column of ejected material. .We utilize this craterlike feature in part in the head ring of'our target-'forming attachment but in order to promote the circulation of air through the crater, we cut away thev innerwall thereof so as to avoid some of the eddies formed when a solid back' or inner wall is present.

We claim: y 1. The method of applying a coating which consists in ejecting a stream of material and then diverting said` stream bydil' recting a jet of gaseous iiuid thereagains't and to one side of the axial-center thereof.

.2. .The method of applying a coating whichl 'consists ejecting a vcolumn ofmaterial and then diverting said column by directing a jet pf' gaseous fluid thereagainst andaat each side of the axial center thereof.

3.Th .method of applying a coating consists in ejecting `a' 'co1umn of material, and then diverting said .column by di-` (gaseous fluid against one side] 5. A spray gun having airv and paint conduits, a valve seat having a plurality .of airl ports communicating with: the air conduit, a member movable with relation to said valve seat. and provided with'ports which are designed tobe successively registered with ,ports in the valve seat and to eject streams 'of air having non-intersecting center lines.-

6. The combinationl of a spray-gun having J means for delivering a columnof material under pressure and against a surface to be coatedathereby producing a circular target, and meansA for directing a blast of air against one edge only of said column of material to produce a non-circular target.

7. The combination of a spray-gun havin means for delivering a column of materia under pressure and against a surface to-be coated, thereby producing a circular target,

and adjustable means for diverting said column of material to produce a plurality of targets of unilateral and bilateral shapes,

said adjusting means includingat leastone auxiliary passage adapted to eject a stream of air vagainst 'saidcolumn ofinaterial in of said column. v.

8. A target-forming memberfor spraying spaced arms, and a head ring, having a craterlike '.face and provided with ,air blast ports in the sides of the crater.

9. Spray producing means, in combination,

a direction disaligned with the axial center with a target-forming ring having. a craterlike recess'throughthe center of which thevv spray is ejected, blast ports in the side walls ofsaid'crater for producing differential targets, and means for differentially controlling said target-forming blastports.

10. An air blast nipple' 'for material,-

spraying-devices, 'comprising a member proivided with an air conduit, aiid means at the.` end of said lconduit for electing a circular series of separate blasts of air. i

V11. An air blast nipple having a main central orifice' for the emission of air under pressure-and a series of smaller orifices disposed around said main orifice.

12. A' mateitial valve formed with an ori-' lice', in combination with an air blast nipple, f

there being a -material supply chamber be.- tween the two, and means for shutting oi the 'supply of the material to said orifice isc by adjusting the edges of said orifice against said nipple.

18. A material valve formed With a centrally arranged orifice and diagonally disposed material ports leading to said orifice, a material supply chamber, there being ports leading therefrom and adapted to register with said diagonally disposed material ports, and means for adjusting said valve to con-l trol the supply of material through said 14. A material valve formed with a centrally arranged orifice, and lateral material ports, means for supplying compressed air to said orifice, a material supply chamber ncommunication with said lateral ports,

means for regulating the supply of material to these ports, and means for placing the compressed air supply in direct communication with said material chamber to cause a flow of air pressure therethrough.

15. A nozzle for air brushes comprising a nozzle casing having a central main opening, and side passages having their outlets inclined slightly forwardly relative to the stream from the .main bore and tangential to said main bore.

In testimony whereof we hereunto alix our signatures this 9th day of August, 1921.

THEODORE BIRKENMAIER. vTAL-TER A. HEINRICH. JOHN B. TRESCOTT. 

